From 1dd0377e313ac65223028aa71847c670ff90a9a9 Mon Sep 17 00:00:00 2001
From: bakk <bakk@tuta.io>
Date: Sun, 16 Jan 2022 21:58:46 +0100
Subject: [PATCH] Allow nested integrals

---
 kalk/src/analysis.rs | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/kalk/src/analysis.rs b/kalk/src/analysis.rs
index edfd7d2..fd3e465 100644
--- a/kalk/src/analysis.rs
+++ b/kalk/src/analysis.rs
@@ -597,10 +597,12 @@ fn build_fn_call(
     log_base: Option<Expr>,
 ) -> Result<Expr, CalcError> {
     let is_integral = identifier.pure_name == "integrate";
+    let prev_in_integral = context.in_integral;
     if is_integral {
         context.in_integral = true;
     }
 
+    let prev_in_sum_prod = context.in_sum_prod;
     let is_sum_prod = identifier.pure_name == "sum" || identifier.pure_name == "prod";
     if is_sum_prod {
         context.in_sum_prod = true;
@@ -652,11 +654,11 @@ fn build_fn_call(
     };
 
     if is_integral {
-        context.in_integral = false;
+        context.in_integral = prev_in_integral;
     }
 
     if is_sum_prod {
-        context.in_sum_prod = false;
+        context.in_sum_prod = prev_in_sum_prod;
     }
 
     Ok(Expr::FnCall(identifier, arguments))